顾旺旺，王哲，尹兆雷，孙晨乐

(同济大学新能源工程中心，上海 201804)

摘 要：自由活塞直线发电机系统是由直线发动机与直线电机耦合而成，将燃料的化学能直接转化成电能的一种发电装置。活塞运动的控制是该系统控制中的难点，其活塞上止点对系统稳定运行的影响大，所以必须保证上止点的稳定。文章中提出一种基于活塞中点速度预测的电磁力控制策略，根据检测到的活塞中点速度，调节电磁力负载，使得活塞运动上止点保持稳定。为验证该控制策略的控制效果，搭建了仿真模型，并对搭建的系统仿真模型进行了试验验证，试验结果与仿真吻合较好。仿真研究表明，在发动机喷油量发生随机波动时，该控制策略很好地稳定了活塞运动上止点。

关键词：自由活塞发动机；直线电机；稳定控制；上止点

Abstract: Free-piston linear generator is the combination of free-piston engine and linear electrical machine, and can change the chemical energy of fuel into electricity directly. The main challenge with such system is the control of the piston motion. Due to the great influence on the steady running of the system, the stability of the top dead center (TDC) must be ensured. A control strategy that to adjust the generator force based on the speed of midpoint is proposed in this paper. Then a simulation model which was verified by the test is built to verify the control strategy. It is found that the control strategy can ensure the stability of the TDC effectively when the injected fuel mass changed randomly.

key words: Free-piston engine; Linear generator; Stability control; Top dead center